With the rapid development of the mobile communication technology, mobile terminal devices represented by mobile phones bring great convenience to people's lives, and all these are based on good network coverage. However, according to characteristics of the mobile network itself, the mobile network is hard to cover all corners to which the mobile terminal may move, such as, mountainous areas, at sea, underground garages and high-rise included angles and so on. All these coverage dead angles bring much inconvenience to the use of the mobile terminal and also influence the user experience greatly. In order to make up the inconvenience which coverage blind areas and dead angles of the wireless network bring to the users, loss resulted from no signal to the users can be reduced through certain advance prompts, which improves the user experience.
In the related art, after there have been no signal in the mobile terminal, that is, it has already entered the network coverage blind area, a no-signal prompt is given to the user, and the user may feel that the no-signal prompt of the mobile terminal is too late. Therefore, a new technical scheme is required, before the mobile terminal enters the network coverage blind area, a relevant warning prompt is given to the user, so as to improve the user experience of the mobile terminal.